H. Ma, K. Schewe. Conceptual geometric modelling. pages 421-440, 3, 2011.
- Hui Ma
- Klaus-Dieter Schewe
|Buch||Handbook of Conceptual Modelling|
||This chapter starts with a review of existing spatial data models in the literature to shows some key problems that need to be addressed by conceptual models to include spatial data and more generally geometric data. Motivated among others by the need to support spatial modelling for the sustainable land use initiative we present a geometrically enhanced ER model (GERM), which preserves the key principles of ER modelling and at the same time introduces bulk constructions and types that support geometric objects. The model distinguishes between a syntactic level of types and an explicit internal level, in which types give rise to polyhedra that are defined by algebraic varieties. It further emphasises the stability of algebraic operations by means of a natural modelling algebra that extends the usual Boolean operations on point sets.